[v2,4/5] kconfig: refactor Makefile to reduce process forks

  Refactor Makefile and use read-file macro. For Make >= 4.2, it can read
out a file by using the built-in function.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

(no changes since v1)

 scripts/kconfig/.gitignore   |  4 +++-
 scripts/kconfig/Makefile     | 43 +++++++++++++++++++-----------------
 scripts/kconfig/gconf-cfg.sh |  7 ++++--
 scripts/kconfig/mconf-cfg.sh | 25 ++++++++++++---------
 scripts/kconfig/nconf-cfg.sh | 23 ++++++++++---------
 scripts/kconfig/qconf-cfg.sh | 10 ++++++---
 scripts/remove-stale-files   |  2 ++
 7 files changed, 67 insertions(+), 47 deletions(-)
  

On Thu 24 Nov 2022 00:18:27 GMT, Masahiro Yamada wrote:
> Refactor Makefile and use read-file macro. For Make >= 4.2, it can 
> read
> out a file by using the built-in function.
> 
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---

Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

> 
> (no changes since v1)
> 
>  scripts/kconfig/.gitignore   |  4 +++-
>  scripts/kconfig/Makefile     | 43 +++++++++++++++++++-----------------
>  scripts/kconfig/gconf-cfg.sh |  7 ++++--
>  scripts/kconfig/mconf-cfg.sh | 25 ++++++++++++---------
>  scripts/kconfig/nconf-cfg.sh | 23 ++++++++++---------
>  scripts/kconfig/qconf-cfg.sh | 10 ++++++---
>  scripts/remove-stale-files   |  2 ++
>  7 files changed, 67 insertions(+), 47 deletions(-)
> 
> diff --git a/scripts/kconfig/.gitignore b/scripts/kconfig/.gitignore
> index 500e7424b3ef..c8a3f9cd52f0 100644
> --- a/scripts/kconfig/.gitignore
> +++ b/scripts/kconfig/.gitignore
> @@ -1,5 +1,7 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  /conf
>  /[gmnq]conf
> -/[gmnq]conf-cfg
> +/[gmnq]conf-cflags
> +/[gmnq]conf-libs
> +/qconf-bin
>  /qconf-moc.cc
> diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
> index b8ef0fb4bbef..da7da9775a4b 100644
> --- a/scripts/kconfig/Makefile
> +++ b/scripts/kconfig/Makefile
> @@ -159,11 +159,12 @@ conf-objs	:= conf.o $(common-objs)
>  hostprogs	+= nconf
>  nconf-objs	:= nconf.o nconf.gui.o $(common-objs)
>  
> -HOSTLDLIBS_nconf	= $(shell . $(obj)/nconf-cfg && echo $$libs)
> -HOSTCFLAGS_nconf.o	= $(shell . $(obj)/nconf-cfg && echo $$cflags)
> -HOSTCFLAGS_nconf.gui.o	= $(shell . $(obj)/nconf-cfg && echo $$cflags)
> +HOSTLDLIBS_nconf       = $(call read-file, $(obj)/nconf-libs)
> +HOSTCFLAGS_nconf.o     = $(call read-file, $(obj)/nconf-cflags)
> +HOSTCFLAGS_nconf.gui.o = $(call read-file, $(obj)/nconf-cflags)
>  
> -$(obj)/nconf.o $(obj)/nconf.gui.o: $(obj)/nconf-cfg
> +$(obj)/nconf: | $(obj)/nconf-libs
> +$(obj)/nconf.o $(obj)/nconf.gui.o: | $(obj)/nconf-cflags
>  
>  # mconf: Used for the menuconfig target based on lxdialog
>  hostprogs	+= mconf
> @@ -171,27 +172,28 @@ lxdialog	:= $(addprefix lxdialog/, \
>  		     checklist.o inputbox.o menubox.o textbox.o util.o yesno.o)
>  mconf-objs	:= mconf.o $(lxdialog) $(common-objs)
>  
> -HOSTLDLIBS_mconf = $(shell . $(obj)/mconf-cfg && echo $$libs)
> +HOSTLDLIBS_mconf = $(call read-file, $(obj)/mconf-libs)
>  $(foreach f, mconf.o $(lxdialog), \
> -  $(eval HOSTCFLAGS_$f = $$(shell . $(obj)/mconf-cfg && echo $$$$cflags)))
> +  $(eval HOSTCFLAGS_$f = $$(call read-file, $(obj)/mconf-cflags)))
>  
> -$(addprefix $(obj)/, mconf.o $(lxdialog)): $(obj)/mconf-cfg
> +$(obj)/mconf: | $(obj)/mconf-libs
> +$(addprefix $(obj)/, mconf.o $(lxdialog)): | $(obj)/mconf-cflags
>  
>  # qconf: Used for the xconfig target based on Qt
>  hostprogs	+= qconf
>  qconf-cxxobjs	:= qconf.o qconf-moc.o
>  qconf-objs	:= images.o $(common-objs)
>  
> -HOSTLDLIBS_qconf	= $(shell . $(obj)/qconf-cfg && echo $$libs)
> -HOSTCXXFLAGS_qconf.o	= $(shell . $(obj)/qconf-cfg && echo $$cflags)
> -HOSTCXXFLAGS_qconf-moc.o = $(shell . $(obj)/qconf-cfg && echo $$cflags)
> -
> -$(obj)/qconf.o: $(obj)/qconf-cfg
> +HOSTLDLIBS_qconf         = $(call read-file, $(obj)/qconf-libs)
> +HOSTCXXFLAGS_qconf.o     = -std=c++11 -fPIC $(call read-file, $(obj)/qconf-cflags)
> +HOSTCXXFLAGS_qconf-moc.o = -std=c++11 -fPIC $(call read-file, $(obj)/qconf-cflags)
> +$(obj)/qconf: | $(obj)/qconf-libs
> +$(obj)/qconf.o $(obj)/qconf-moc.o: | $(obj)/qconf-cflags
>  
>  quiet_cmd_moc = MOC     $@
> -      cmd_moc = $(shell . $(obj)/qconf-cfg && echo $$moc) $< -o $@
> +      cmd_moc = $(call read-file, $(obj)/qconf-bin)/moc $< -o $@
>  
> -$(obj)/qconf-moc.cc: $(src)/qconf.h $(obj)/qconf-cfg FORCE
> +$(obj)/qconf-moc.cc: $(src)/qconf.h FORCE | $(obj)/qconf-bin
>  	$(call if_changed,moc)
>  
>  targets += qconf-moc.cc
> @@ -200,15 +202,16 @@ targets += qconf-moc.cc
>  hostprogs	+= gconf
>  gconf-objs	:= gconf.o images.o $(common-objs)
>  
> -HOSTLDLIBS_gconf    = $(shell . $(obj)/gconf-cfg && echo $$libs)
> -HOSTCFLAGS_gconf.o  = $(shell . $(obj)/gconf-cfg && echo $$cflags)
> +HOSTLDLIBS_gconf   = $(call read-file, $(obj)/gconf-libs)
> +HOSTCFLAGS_gconf.o = $(call read-file, $(obj)/gconf-cflags)
>  
> -$(obj)/gconf.o: $(obj)/gconf-cfg
> +$(obj)/gconf: | $(obj)/gconf-libs
> +$(obj)/gconf.o: | $(obj)/gconf-cflags
>  
>  # check if necessary packages are available, and configure build flags
> -filechk_conf_cfg = $(CONFIG_SHELL) $<
> +cmd_conf_cfg = $< $(addprefix $(obj)/$*conf-, cflags libs bin)
>  
> -$(obj)/%conf-cfg: $(src)/%conf-cfg.sh FORCE
> -	$(call filechk,conf_cfg)
> +$(obj)/%conf-cflags $(obj)/%conf-libs $(obj)/%conf-bin: $(src)/%conf-cfg.sh
> +	$(call cmd,conf_cfg)
>  
>  clean-files += *conf-cfg
> diff --git a/scripts/kconfig/gconf-cfg.sh b/scripts/kconfig/gconf-cfg.sh
> index cbd90c28c05f..040d8f338820 100755
> --- a/scripts/kconfig/gconf-cfg.sh
> +++ b/scripts/kconfig/gconf-cfg.sh
> @@ -1,6 +1,9 @@
>  #!/bin/sh
>  # SPDX-License-Identifier: GPL-2.0
>  
> +cflags=$1
> +libs=$2
> +
>  PKG="gtk+-2.0 gmodule-2.0 libglade-2.0"
>  
>  if [ -z "$(command -v ${HOSTPKG_CONFIG})" ]; then
> @@ -26,5 +29,5 @@ if ! ${HOSTPKG_CONFIG} --atleast-version=2.0.0 gtk+-2.0; then
>  	exit 1
>  fi
>  
> -echo cflags=\"$(${HOSTPKG_CONFIG} --cflags $PKG)\"
> -echo libs=\"$(${HOSTPKG_CONFIG} --libs $PKG)\"
> +${HOSTPKG_CONFIG} --cflags ${PKG} > ${cflags}
> +${HOSTPKG_CONFIG} --libs ${PKG} > ${libs}
> diff --git a/scripts/kconfig/mconf-cfg.sh b/scripts/kconfig/mconf-cfg.sh
> index 025b565e0b7c..1e61f50a5905 100755
> --- a/scripts/kconfig/mconf-cfg.sh
> +++ b/scripts/kconfig/mconf-cfg.sh
> @@ -1,19 +1,22 @@
>  #!/bin/sh
>  # SPDX-License-Identifier: GPL-2.0
>  
> +cflags=$1
> +libs=$2
> +
>  PKG="ncursesw"
>  PKG2="ncurses"
>  
>  if [ -n "$(command -v ${HOSTPKG_CONFIG})" ]; then
>  	if ${HOSTPKG_CONFIG} --exists $PKG; then
> -		echo cflags=\"$(${HOSTPKG_CONFIG} --cflags $PKG)\"
> -		echo libs=\"$(${HOSTPKG_CONFIG} --libs $PKG)\"
> +		${HOSTPKG_CONFIG} --cflags ${PKG} > ${cflags}
> +		${HOSTPKG_CONFIG} --libs ${PKG} > ${libs}
>  		exit 0
>  	fi
>  
> -	if ${HOSTPKG_CONFIG} --exists $PKG2; then
> -		echo cflags=\"$(${HOSTPKG_CONFIG} --cflags $PKG2)\"
> -		echo libs=\"$(${HOSTPKG_CONFIG} --libs $PKG2)\"
> +	if ${HOSTPKG_CONFIG} --exists ${PKG2}; then
> +		${HOSTPKG_CONFIG} --cflags ${PKG2} > ${cflags}
> +		${HOSTPKG_CONFIG} --libs ${PKG2} > ${libs}
>  		exit 0
>  	fi
>  fi
> @@ -22,22 +25,22 @@ fi
>  # (Even if it is installed, some distributions such as openSUSE cannot
>  # find ncurses by pkg-config.)
>  if [ -f /usr/include/ncursesw/ncurses.h ]; then
> -	echo cflags=\"-D_GNU_SOURCE -I/usr/include/ncursesw\"
> -	echo libs=\"-lncursesw\"
> +	echo -D_GNU_SOURCE -I/usr/include/ncursesw > ${cflags}
> +	echo -lncursesw > ${libs}
>  	exit 0
>  fi
>  
>  if [ -f /usr/include/ncurses/ncurses.h ]; then
> -	echo cflags=\"-D_GNU_SOURCE -I/usr/include/ncurses\"
> -	echo libs=\"-lncurses\"
> +	echo -D_GNU_SOURCE -I/usr/include/ncurses > ${cflags}
> +	echo -lncurses > ${libs}
>  	exit 0
>  fi
>  
>  # As a final fallback before giving up, check if $HOSTCC knows of a default
>  # ncurses installation (e.g. from a vendor-specific sysroot).
>  if echo '#include <ncurses.h>' | ${HOSTCC} -E - >/dev/null 2>&1; then
> -	echo cflags=\"-D_GNU_SOURCE\"
> -	echo libs=\"-lncurses\"
> +	echo -D_GNU_SOURCE > ${cflags}
> +	echo -lncurses > ${libs}
>  	exit 0
>  fi
>  
> diff --git a/scripts/kconfig/nconf-cfg.sh b/scripts/kconfig/nconf-cfg.sh
> index 3a10bac2adb3..f871a2160e36 100755
> --- a/scripts/kconfig/nconf-cfg.sh
> +++ b/scripts/kconfig/nconf-cfg.sh
> @@ -1,19 +1,22 @@
>  #!/bin/sh
>  # SPDX-License-Identifier: GPL-2.0
>  
> +cflags=$1
> +libs=$2
> +
>  PKG="ncursesw menuw panelw"
>  PKG2="ncurses menu panel"
>  
>  if [ -n "$(command -v ${HOSTPKG_CONFIG})" ]; then
>  	if ${HOSTPKG_CONFIG} --exists $PKG; then
> -		echo cflags=\"$(${HOSTPKG_CONFIG} --cflags $PKG)\"
> -		echo libs=\"$(${HOSTPKG_CONFIG} --libs $PKG)\"
> +		${HOSTPKG_CONFIG} --cflags ${PKG} > ${cflags}
> +		${HOSTPKG_CONFIG} --libs ${PKG} > ${libs}
>  		exit 0
>  	fi
>  
>  	if ${HOSTPKG_CONFIG} --exists $PKG2; then
> -		echo cflags=\"$(${HOSTPKG_CONFIG} --cflags $PKG2)\"
> -		echo libs=\"$(${HOSTPKG_CONFIG} --libs $PKG2)\"
> +		${HOSTPKG_CONFIG} --cflags ${PKG2} > ${cflags}
> +		${HOSTPKG_CONFIG} --libs ${PKG2} > ${libs}
>  		exit 0
>  	fi
>  fi
> @@ -22,20 +25,20 @@ fi
>  # (Even if it is installed, some distributions such as openSUSE cannot
>  # find ncurses by pkg-config.)
>  if [ -f /usr/include/ncursesw/ncurses.h ]; then
> -	echo cflags=\"-D_GNU_SOURCE -I/usr/include/ncursesw\"
> -	echo libs=\"-lncursesw -lmenuw -lpanelw\"
> +	echo -D_GNU_SOURCE -I/usr/include/ncursesw > ${cflags}
> +	echo -lncursesw -lmenuw -lpanelw > ${libs}
>  	exit 0
>  fi
>  
>  if [ -f /usr/include/ncurses/ncurses.h ]; then
> -	echo cflags=\"-D_GNU_SOURCE -I/usr/include/ncurses\"
> -	echo libs=\"-lncurses -lmenu -lpanel\"
> +	echo -D_GNU_SOURCE -I/usr/include/ncurses > ${cflags}
> +	echo -lncurses -lmenu -lpanel > ${libs}
>  	exit 0
>  fi
>  
>  if [ -f /usr/include/ncurses.h ]; then
> -	echo cflags=\"-D_GNU_SOURCE\"
> -	echo libs=\"-lncurses -lmenu -lpanel\"
> +	echo -D_GNU_SOURCE > ${cflags}
> +	echo -lncurses -lmenu -lpanel > ${libs}
>  	exit 0
>  fi
>  
> diff --git a/scripts/kconfig/qconf-cfg.sh b/scripts/kconfig/qconf-cfg.sh
> index ad652cb53947..117f36e568fc 100755
> --- a/scripts/kconfig/qconf-cfg.sh
> +++ b/scripts/kconfig/qconf-cfg.sh
> @@ -1,6 +1,10 @@
>  #!/bin/sh
>  # SPDX-License-Identifier: GPL-2.0
>  
> +cflags=$1
> +libs=$2
> +bin=$3
> +
>  PKG="Qt5Core Qt5Gui Qt5Widgets"
>  
>  if [ -z "$(command -v ${HOSTPKG_CONFIG})" ]; then
> @@ -11,9 +15,9 @@ if [ -z "$(command -v ${HOSTPKG_CONFIG})" ]; then
>  fi
>  
>  if ${HOSTPKG_CONFIG} --exists $PKG; then
> -	echo cflags=\"-std=c++11 -fPIC $(${HOSTPKG_CONFIG} --cflags $PKG)\"
> -	echo libs=\"$(${HOSTPKG_CONFIG} --libs $PKG)\"
> -	echo moc=\"$(${HOSTPKG_CONFIG} --variable=host_bins Qt5Core)/moc\"
> +	${HOSTPKG_CONFIG} --cflags ${PKG} > ${cflags}
> +	${HOSTPKG_CONFIG} --libs ${PKG} > ${libs}
> +	${HOSTPKG_CONFIG} --variable=host_bins Qt5Core > ${bin}
>  	exit 0
>  fi
>  
> diff --git a/scripts/remove-stale-files b/scripts/remove-stale-files
> index ccadfa3afb2b..64b14aa5aebf 100755
> --- a/scripts/remove-stale-files
> +++ b/scripts/remove-stale-files
> @@ -47,3 +47,5 @@ rm -f arch/riscv/purgatory/kexec-purgatory.c
>  rm -f scripts/extract-cert
>  
>  rm -f arch/x86/purgatory/kexec-purgatory.c
> +
> +rm -f scripts/kconfig/[gmnq]conf-cfg
> -- 
> 2.34.1